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Astronomer Discovers the Most Distant Stars Ever Observed From Earth
Cryolithic writes to tell us The Vancouver Sun is reporting that a University of B.C. astronomer recently used NASA's Hubble telescope to see a cluster of stars one billion light-years from Earth, the farthest stars ever observed from Earth. From the article: "That's interesting, he explains, because given that light travels at a finite speed -- 300,000 km a second -- the light emitted from the star cluster he and Kalirai saw was emitted one billion years ago. That means the cluster as it appeared to them two months ago was the way it looked one billion years ago. In other words, they were looking one billion years back in time."
So, when I look at the sun, I am actually looking back in time 8 minutes?
Yes, and apparently, 8 minutes ago hurts like a motherfucker.
The theory of relativity doesn't work right in Arkansas.
Travelling 1 billion years at the fastest possible speed known to science doesn't even get us to the edge of the universe.
Ahh, but the beauty of it is that if you _DID_ travel at or near the speed of light, one billion years would not seem like such a long time at all - certainly doable within a lifetime! So if you asked those photons how old they thought they were, you'd be surprised at the answer... so the photons aren't really that old at all! Confused yet?
Seven puppies were harmed during the making of this post.
As an astronomy graduate student, I would like to offer a correction or an explanation of this statement:
From the article:
"That's because the older a star gets, the redder it gets, he says. Younger stars are bluer."
Kinda true, but the point is something else. A young *cluster* of stars will look blue because brightest stars in a young cluster are blue, massive stars. These blue bright stars burn their fuel (Hydrogen) very fast and have short lives (~100 Million years). When blue bright stars go away, more numerous, but much fainter, red stars start to dominate the color of the cluster. Therefore, as the *cluster* gets older, it gets redder.
...in a vacuum. When not in a vacuum, light can travel at a fraction of the speed of light.
Well no, not exactly. When not in a vacuum it takes rest stops which reduce its average speed, but when not taking rest stops it travels at the designated finite speed; because that's the only speed at which light can travel. There was this Maxwell guy who 'splained it.
You know about the pony express? Well, they had posts along the way to change horses. Let's say, for the sake of simplicity, that these posts were 15 miles apart and that the horses traveled at a finite speed of 15 miles per hour. When the horse is moving it is always going 15 miles per hour, but the average speed of the horses over a full day is 13 miles per hour because of the time it takes for the rider to change them on an hourly basis.
Light is like the Pony Express, only without the horses, which wouldn't be like the Pony Express at all, would it? That would just be some guy taking a walk.
Nevermind.
KFG
Anyone who has ever watched a Roadrunner vs. Wyle E. Coyote cartoon knows this.
I may twist orthodoxy to partly justify a tyrant. But I can easily make up a German philosophy to justify him entirely.